Accession Number : ADA290160

Title :   Surface Fatigue Life of High Temperature Gear Materials.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Townsend, Dennis P.

PDF Url : ADA290160

Report Date : APR 1994

Pagination or Media Count : 13

Abstract : Three high temperature gear materials were evaluated using spur gear surface fatigue tests. These materials were, VASCO max 350, VASCO matrix H, and nitralloy N and were evaluated for possible use in high temperature gear applications. The fatigue life of the three high temperature gear materials were compared with the life of the standard AISI 9310 aircraft gear material. Surface fatigue tests were conducted at a lubricant inlet temperature of 321 K (120 deg F), a lubricant outlet temperature of 350 K (170 deg F), a maximum Hertz stress of 1.71 GPa (248 ksi), a speed of 10000 rpm and with a synthetic paraffinic lubricant. The life of the nitralloy N was approximately the same as the MSI 9310, the life of the VASCO max 350 was much less than the AISI 9310 while the life of the VASCO matrix H was several times the life of the AISI 9310. The VASCO max 350 also showed very low fracture toughness with approximately half of the gears failed by tooth fracture through the fatigue spall. The VASCO matrix II had approximately 10-percent fracture failure through the fatigue spalls indicating moderate to good fracture toughness. (MM)

Descriptors :   *GEARS, VIBRATION, AIRCRAFT, FATIGUE LIFE, TOUGHNESS, MATRIX MATERIALS, ALLOYS, STEEL, FRACTURE(MECHANICS), GAS TURBINES, FAILURE(MECHANICS), HARDNESS, LUBRICANTS, FATIGUE TESTS(MECHANICS), SPALLATION, GEAR TEETH.

Subject Categories : Laminates and Composite Materials
      Machinery and Tools
      Aircraft
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE